1. Related Applications
This application is a continuation-in-part of co-pending application Ser. No. 07/031,696, which issued as U.S. Pat. No. 4,795,221 on Jan. 3, 1989.
1. Field of the Invention
The present invention relates generally to endless traction belts or tracks used in driving snowmobiles. In particular, the present invention relates to improved cleats made of a flexible, resilient, elastomeric material and which when installed on the track of the snowmobile will greatly improve the ability of the track of the snowmobile to lift the track and the snowmobile upon snow, to drive the snowmobile at relatively high velocities over the snow and to propel the snowmobile over deep, powder snow.
2. State of the Art
Snowmobiles are used extensively in snowy regions, not only for everyday use, but they are also used widely for recreational and emergency purposes. Snowmobiles are operated on a wide variety of terrain. They are used in hilly or mountainous regions as well as on flat land. They are operated on fresh snow, on trails conditioned for snowmobile riding, on hard packed snow, on the icy surfaces of streams, rivers, and lakes, and on hard snow packed or icy roads.
Continuous drive tracks are conventionally used for engaging the snow covered surface, the icy surface or the surface of a body of water in order to provide the propulsion to move the snowmobile forward. In order to provide proper traction on snow and ice, as well as for uphill downhill and other conditions in which snowmobiles are used, the design of the track is very important. Generally speaking, the traction belt or track has a width substantially equal to the seat portion at the rear of the snowmobile. The track is drivably suspended on the frame of the snowmobile and is generally positioned at the rear portion of the snowmobile, while a pair of steerable skis support the front end of the snowmobile.
An example of a conventional track for a snowmobile is shown in U.S. Pat. No. 3,623,780. The track is generally made of an elastomeric material, with a plurality of transversely mounted and longitudinally spaced, rigid, elongate drive cleats being secured or mounted on the outside of the track. The drive cleats, which are conventionally U-shaped in cross-section, provide traction with the terrain in order to propel the snowmobile in a forward direction. Braking of the snowmobile is also accomplished utilizing the track. In braking, the track is slowed or stopped, and the cleats on the track then dig into the snow or ice on the ground to slow and stop the snowmobile.
Although there are innumerable snowmobiles in use, all of which utilize tracks having some type traction means such as the cleats mentioned above, the drive systems comprising such tracts are not without problems which can be irritable and downright troublesome to the snowmobiler. When the snowmobile is bucking deep snow, attempting to climb hills, breaking a new trail through snow, or is being operated in numerous other modes involving high load conditions wherein traction is of great importance, the traction means, such as the cleats mentioned above, have a universal tendency to dig deeply into the snow and ultimately bog the snowmobile down in the snow. Heretofore, there has been no provision by which the track could be designed to provide necessary traction while at the same time providing lift for the track and the snowmobile to keep the track from digging deep into the snow and bogging the snowmobile down.
In U.S. Pat. No. 4,175,627, there is disclosed a lightweight propulsion system for a power driven ski device in which a continuous drive track is provided. The drive track is relatively small and lightweight, with the drive track having a width which is approximately only that of a ski. The drive track comprises resilient cleats which extent transversely across the width of the track and are spaced along the circumferential length of the track. The cleats comprise substantially flat fins which are angled with respect to the outer, longitudinal surface of the track, with the flat cleats making an acute angle with the surface of the track such that the cleats slant forward in a direction of rotation of the track as the track is driven in its normal operation of propelling the power driven ski device forward. The cleats, slanting forwardly in the direction of rotation of the track, dig downwardly into the snow to provide traction for the otherwise lightweight, power driven ski device. However, if such forward slanting cleats were used on a relatively heavy weight snowmobile, the track would quickly dig itself deeply into the snow and completely bog the snowmobile down.
3. Objectives
A principal objective of the invention is to provide a novel, resilient, flexible cleat which is readily attached by a single attachment member to the outer surface of an endless traction belt or track used in driving snowmobiles, with the flexible cleat comprising a relatively narrow, elongate, essentially planar fin or strip of resilient material extending outwardly from the snowmobile track and a relatively narrow, elongate, essentially planar mounting flange extending along an elongate side edge of the fin for mounting flatwise against the outer surface of the snowmobile track, wherein a series of sharp projections extend from the face of the flange to engage the outer surface of the snowmobile track to stabilize the cleat relative to the track.
A particular objective of the present invention is to provide a plurality of such resilient, flexible cleats attached to and spaced about the length of the track of a snowmobile, 1 wherein the fins are oriented to slope from the surface of the snowmobile track at an acute angle and in the opposite direction of travel or rotation of the snowmobile track, whereby such track not only exhibits exceptional traction for high speed but also develops an unexpected lift which pulls the track and the snowmobile upwardly and over the surface of snow when the snowmobile is being operated over light or deep snow.
Another objective of the present invention is to provide inexpensive, resilient, flexible cleats which can be quickly and easily installed on essentially all conventional tracks used in propelling snowmobiles to increase the effective traction of such tracks and in addition to provide such tracks with a completely unexpected lift characteristic in combination with the increased traction.